Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. The Soviet project to develop an atomic bomb was a clandestine research and development program begun during and post-World War II, in the wake of the Soviet Union's discovery of the United States' nuclear project. However, because of the bloody and intensified war with Germany on the Eastern Front, the large scale efforts prevented Soviets from developing the atomic bomb, but accelerated the program after the American atomic bombings of Hiroshima and Nagasaki, thus putting an end to World War II. After the Japanese surrender in 1945, the Soviet Union expanded its research facilities, military reactors, and employed a number of scientists, including its atomic spies who successfully penetrated the American nuclear weapons efforts. The Soviet Union's research and espionage ultimately led them to conduct the first test of its implosion-type nuclear device, codename First Lightning on 29 August 1949, at Semipalatinsk, Kazakh SSR. Learn more about the Russian nuclear weapons program from its inception till the present day in the following pages.